Classification of Vitamins
Vitamins widely vary from each other from tlie structural point of view. Conventionally, they are classified on the basis of their solubility in water or fat. Accordingly, they are classified as:
Water soluble vitamins, which include thiamin (vitamin B1), riboflavi'n (vitamin B?), niacin and nicotinamide (vitamin B3), pantothenic acid (vitamin B5), pyridoxine and related compounds (vitamin B6), cyanocobalamin and related
compounds (vitamin Biz), ascorbic acid (vitamin C), biotin (vitamin H) and folic acid (vitamin M).
Fat-soluble vitamins, which include retinol (vitamin A), cholecalciferol (vitamin D), tocopherols (vitamin E)